The moon really does appear larger when it is near the horizon. But its real angular size is no greater than when it is high in the sky.

Earth’s atmosphere near the horizon raises the moon slightly in the sky. This refraction becomes greater at the horizon and consequently the moon appears flattened. Also, compared to an airless world, the moon and stars rise early and set late.

Refraction has another effect. It is weakest for red light. The ‘red moon’ is raised least. Near the horizon, as here, the moon has a thin red lower rim and a green upper one.